This study aimed to investigate the oncolytic efficacy of S. pyogenes GUR and its M protein knockout mutant, S. pyogenes strain GURSA1, which was genetically constructed to minimize overall toxicity, against mouse hepatoma 22A, pancreatic cancer PANC02, and human glioma U251 cells, both in vitro and in vivo, using the C57BL/6 mouse model. The gene discussed is MYOM2; the disease is central nervous system cancer.